Percutaneous Left Atrial Appendage Occlusion for the Prevention of Stroke in Patients with Atrial Fibrillation: Review and Critical Appraisal

Stand-Alone Left Atrial appendage occlusion for throMboembolism prevention in nonvalvular Atrial fibrillatioN DiseasE Registry (SALAMANDER): protocol for a prospective observational nationwide study

INTRODUCTION

Atrial fibrillation (AF) is a prevalent disease considerably contributing to the worldwide cardiovascular burden. For patients at high thromboembolic risk (CHA₂DS₂-VASc ≥3) and not suitable for chronic oral anticoagulation, owing to history of major bleeding or other contraindications, left atrial appendage occlusion (LAAO) is indicated for stroke prevention, as it lowers patient's ischaemic burden without augmentation in their anticoagulation profile.

METHODS AND ANALYSIS

Stand-Alone Left Atrial appendage occlusion for throMboembolism prevention in nonvalvular Atrial fibrillatioN DiseasE Registry (SALAMANDER) will be conducted in 10 heart surgery and cardiology centres across Poland to assess the outcomes of LAAO performed by fully thoracoscopic-epicardial, percutaneous-endocardial or hybrid endo-epicardial approach. The registry will include patients with nonvalvular AF at a high risk of thromboembolic and bleeding complications (CHA2DS2-VASc Score ≥2 for males, ≥3 for females, HASBLED score ≥2) referred for LAAO. The first primary outcome is composite procedure-related complications, all-cause death or major bleeding at 12 months. The second primary outcome is a composite of ischaemic stroke or systemic embolism at 12 months. The third primary outcome is the device-specific success assessed by an independent core laboratory at 3-6 weeks. The quality of life (QoL) will be assessed as well based on the QoL EQ-5D-5L questionnaire. Medication and drug adherence will be assessed as well.

ETHICS AND DISSEMINATION

Before enrolment, a detailed explanation is provided by the investigator and patients are given time to make an informed decision. The patient's data will be protected according to the requirements of Polish law, General Data Protection Regulation (GDPR) and hospital Standard Operating Procedures. The study will be conducted in accordance with the Declaration of Helsinki. Ethical approval was granted by the local Bioethics Committee of the Upper-Silesian Medical Centre of the Silesian Medical University in Katowice (decision number KNW/0022/KB/284/19). The results will be published in peer-reviewed journals and presented during national and international conferences.

TRIAL REGISTRATION NUMBER

NCT05144958.

Left Atrial Appendage Occlusion: Current Stroke Prevention Strategies and a Shift Toward Data-Driven, Patient-Specific Approaches

The left atrial appendage (LAA) is a complex structure with unknown physiologic function protruding from the main body of the left atrium. In patients with atrial fibrillation, the left atrium does not contract effectively. Insufficient atrial and LAA contractility predisposes the LAA morphology to hemostasis and thrombus formation, leading to an increased risk of cardioembolic events. Oral anticoagulation therapies are the mainstay of stroke prevention options for patients; however, not all patients are candidates for long-term oral anticoagulation. Percutaneous occlusion devices are an attractive alternative to long-term anticoagulation therapy, although they are not without limitations, such as peri-implant leakage and device-related thrombosis. Although efforts have been made to reduce these risks, significant interpatient heterogeneity inevitably yields some degree of device-anatomy mismatch that is difficult to resolve using current devices and can ultimately lead to insufficient occlusion and poor patient outcomes. In this state-of-the-art review, we evaluated the anatomy of the LAA as well as the current pathophysiologic understanding and stroke prevention strategies used in the management of the risk of stroke associated with atrial fibrillation. We highlighted recent advances in computed tomography imaging, preprocedural planning, computational modeling, and novel additive manufacturing techniques, which represent the tools needed for a paradigm shift toward patient-centric LAA occlusion. Together, we envisage that these techniques will facilitate a pipeline from the imaging of patient anatomy to patient-specific computational and bench-top models that enable customized, data-driven approaches for LAA occlusion that are engineered specifically to meet each patient's unique needs.

A Comparative Study of Three Imaging Modalities for Size Selection of a Watchman Left Atrial Appendage Closure Device

PURPOSE

To compare the results of computed tomography angiography (CTA), transesophageal echocardiography (TEE), and digital subtraction angiography (DSA) measurements and analyze their accuracy, correlation, and consistency in patients who have successfully undergone left atrial appendage closure (LAAC).

MATERIALS AND METHODS

A total of 157 non-valvular atrial fibrillation (AF) patients who underwent LAAC with Watchman devices were included in the study. The maximum diameter and depth of LAA were recorded using CTA, TEE, and DSA. Correlations and agreements were compared.

RESULTS

The LAAC procedure was performed successfully in all patients using the Watchman device. There was no significant difference between DSA and TEE measurements of the diameter of the LAA ostium. LAA ostium diameter obtained by CTA, however, was greater than that from DSA and TEE. Correlations were good between LAA ostium diameter measured by TEE, CTA, and DSA and Watchman device size. DSA measurements and actual device size showed the widest limits of agreement, followed by TEE; CTA measurements showed the narrowest limits of agreement. For LAA depth measurements, mean CTA measurements were higher than those of TEE and DSA. There was no significant difference in depth measurements among the three imaging modalities.

CONCLUSION

CTA, TEE, and DSA measurements exhibited good correlations with Watchman device size. The ostium diameter and depth of the LAA measured by CTA were greater than those measured by TEE and DSA. The relevance and concordance of CTA measurements were the strongest.

Thermally responsive hydrogel for atrial fibrillation related stroke prevention

Atrial fibrillation induced stroke accounts for up to 15% of all strokes. These strokes are caused approximately 90% of the time by clot formation in the left atrial appendage (LAA). To prevent these clots, the most common approach is to administer blood thinners. However, contraindications prevent some people from being able to have blood thinners. Devices have been developed to seal the LAA to prevent clot formation in these patients. Current devices, such as the LARIAT® tie off the LAA theoretically preventing blood from entering the LAA. These have had limited clinical success mainly due to failure to completely close the LAA leaving holes and orifices for thrombi to form. To overcome this lack of complete closure, many surgeons use off-label approaches, classically filling the LAA filamentous coils, to cover these holes. Although this usually helps largely cover the holes, placement is challenging, the coils can migrate, the holes are not fully closed as there is space within and around the coils that don't fully mold to the LAA geometry. Furthermore, the coils can develop device related thrombi defeating their purpose. Therefore, these are not fully sufficient to complement the closure techniques in closing the LAA. To address limitation of the closure devices and coil sealing of remaining holes, we developed a thermally responsive hydrogel (Thermogel) that solidifies once injected into the LAA to uniformly and fully close off the LAA thus preventing clot formation and device related thrombi. This Thermogel consists of three portions: 1) a structural component composed of thiolated Pluronic F127 for gel to solid transition following injection, 2) Heparin for anticoagulation, and 3) Dopamine for adhesion to the surrounding endothelium in the turbulent flow encountered in cardiovascular applications. Here we have demonstrated that Thermogel, in conjunction with the LARIAT®, is capable of filling the defects in small and large animals through catheter injection. Thermogel was biocompatible and led to atrophy of the LAA at 5 weeks in a large animal model. Given the advantages of this Thermogel for sealing this defect and ability to be delivered through an endovascular approach, Thermogel presents a viable adjuvant to current occlusion-based treatments for sealing cardiovascular defects.

Asymptomatic Stroke in the Setting of Percutaneous Non-Coronary Intervention Procedures

Advancements in clinical management, pharmacological therapy and interventional procedures have strongly improved the survival rate for cardiovascular diseases (CVDs). Nevertheless, the patients affected by CVDs are more often elderly and present several comorbidities such as atrial fibrillation, valvular heart disease, heart failure, and chronic coronary syndrome. Standard treatments are frequently not available for “frail patients”, in particular due to high surgical risk or drug interaction. In the past decades, novel less-invasive procedures such as transcatheter aortic valve implantation (TAVI), MitraClip or left atrial appendage occlusion have been proposed to treat CVD patients who are not candidates for standard procedures. These procedures have been confirmed to be effective and safe compared to conventional surgery, and symptomatic thromboembolic stroke represents a rare complication. However, while the peri-procedural risk of symptomatic stroke is low, several studies highlight the presence of a high number of silent ischemic brain lesions occurring mainly in areas with a low clinical impact. The silent brain damage could cause neuropsychological deficits or worse, a preexisting dementia, suggesting the need to systematically evaluate the impact of these procedures on neurological function.

Acute Mitral Regurgitation Secondary to Spontaneous Left Atrial Appendage Occluder Migration

A patient underwent left atrial appendage occlusion due to recurrent stroke despite new oral anticoagulant therapy. The patient later presented with severe acute mitral regurgitation secondary to occluder device migration, which was retrieved percutaneously from the descending aorta via the femoral artery. Mitral surgical repair was required and successfully performed. (Level of Difficulty: Intermediate.)

Percutaneous Left Atrial Appendage Occlusion: An Emerging Option in Patients with Atrial Fibrillation at High Risk of Bleeding

Atrial fibrillation (AF) is a common cardiac arrhythmia with an estimated prevalence of 1% in the general population. It is associated with an increased risk of ischemic stroke, silent cerebral ischemia, and cognitive impairment. Due to the blood flow stasis and morphology, thrombus formation occurs mainly in the left atrial appendage (LAA), particularly in the setting of nonvalvular AF (NVAF). Previous studies have shown that >90% of emboli related to NVAF originate from the LAA, thus prevention of systemic cardioembolism is indicated. According to the current guidelines, anticoagulant therapy with direct oral anticoagulants (DOACs) or vitamin K antagonists (VKAs), represents the standard of care in AF patients, in order to prevent ischemic stroke and peripheral embolization. Although these drugs are widely used and DOACs have shown, compared to VKAs, non-inferiority for stroke prevention with significantly fewer bleeding complications, some issues remain a matter of debate, including contraindications, side effects, and adherence. An increasing number of patients, indeed, because of high bleeding risk or after experiencing life-threatening bleedings, must take anticoagulants with extreme caution if not contraindicated. While surgical closure or exclusion of LAA has been historically used in patients with AF with contradictory results, in the recent years, a novel procedure has emerged to prevent the cardioembolic stroke in these patients: The percutaneous left atrial appendage occlusion (LAAO). Different devices have been developed in recent years, though not all of them are approved in Europe and some are still under clinical investigation. Currently available devices have shown a significant decrease in bleeding risk while maintaining efficacy in preventing thromboembolism. The procedure can be performed percutaneously through the femoral vein access, under general anesthesia. A transseptal puncture is required to access left atrium and is guided by transesophageal echocardiography (TEE). Evidence from the current literature indicates that percutaneous LAAO represents a safe alternative for those patients with contraindications for long-term oral anticoagulation. This review summarizes scientific evidences regarding LAAO for stroke prevention including clinical indications and an adequate patient selection.

Atrial Fibrillation and Ischemic Stroke: A Clinical Review

Atrial fibrillation (AF) is an important risk factor for ischemic stroke resulting in a fivefold increased stroke risk and a twofold increased mortality. Our understanding of stroke mechanisms in AF has evolved since the concept of atrial cardiopathy was introduced as an underlying pathological change, with both AF and thromboembolism being common manifestations and outcomes. Despite the strong association with stroke, there is no evidence that screening for AF in asymptomatic patients improves clinical outcomes; however, there is strong evidence that patients with embolic stroke of undetermined source may require long-term monitoring to detect silent or paroxysmal AF. Stroke prevention in patients at risk, assessed by the CHA₂DS₂-VASc score, was traditionally achieved with warfarin; however, direct oral anticoagulants have solidified their role as safe and effective alternatives. Additionally, left atrial appendage exclusion has emerged as a viable option in patients intolerant of anticoagulation. When patients with AF have an acute stroke, the timing of initiation or resumption of anticoagulation for secondary stroke prevention has to be balanced against the risk of hemorrhagic conversion. Multiple randomized clinical trials are currently underway to determine the best timing for administration of anticoagulants following acute ischemic stroke.

Evidence and uncertainties in the management of atrial fibrillation in older persons

INTRODUCTION

Atrial fibrillation (AF) is the most common cardiac sustained arrhythmia, whose incidence and prevalence increase with age, representing a significant burden for health services in western countries. Older people contribute to the vast majority of patients affected from AF.

EVIDENCE ACQUISITION

Although oral anticoagulant therapy represents the cornerstone for the prevention of ischemic stroke and its disabling consequences, several other interventions - including left atrial appendage occlusion (LAAO), catheter ablation (CA) of AF, and rhythm control strategy (RCS) - have proved to be potentially effective in reducing the incidence of AF-associated clinical complications. Scientific literature focused on the three items will be discussed.

EVIDENCE SYNTHESIS

Practical treatment of older AF patients is presented, including approach and management of patients with geriatric syndromes, selection of the most appropriate individualized drug treatment, clinical indications and potential clinical benefit of LAAO and CA in selected older AF patients.

CONCLUSIONS

Older people carry the greatest burden of AF in real world practice. Within a shared decision making process, the patient centered approach need to be put in the context of a comprehensive assessment, in order to gain maximal net clinical benefit and avoid futility or harm.

The Extended Utility of CHA2DS2VASc and HAS-BLED Scores in the Selection for Transcutaneous Left Atrial Appendage Closure

BACKGROUND AND PURPOSE

Left atrial appendage closure (LAAC) is an option for stroke prevention in atrial fibrillation patients. Randomized studies have demonstrated the effectiveness and safety of LAAC but included patients with an average risk of stroke and bleeding complications. The current study aimed to assess the extended utility of CHA2DS2VASc (congestive heart failure; hypertension; age ≥75 years [doubled]; type 2 diabetes; previous stroke, transient ischemic attack, or thromboembolism [doubled]; vascular disease; age 65 to 75 years; and sex category) and HAS-BLED (hypertension; abnormal renal/liver function; stroke; bleeding history or predisposition; labile INR, elderly, drugs/alcohol concomitantly) scores for qualification and prognosis after LAAC.

METHODS

The study population comprised 270 patients aged 72.8 ± 8.78 years. The occluders used were the Amplatzer Amulet (N = 205), Amplatzer Cardiac Plug (N = 53), and Watchman device (N = 12). The prognosis after LAAC was analyzed for different cohorts of patients distinguished based on different CHA2DS2VASc and HAS-BLED scores. The mean duration of follow-up was 21.6 ± 10.3 months.

RESULTS

The observed rates of ischemic stroke and bleeding were much lower than that expected (2.2% vs. 5.6%, and 0.76% vs. 6.05%, respectively). The mortality rate did not differ concerning the CHA2DS2CVASc score. It was significantly lower (8.3%) for HAS-BLED < 3, and it raised to 17.9% for HAS-BLED = 3 and to 25.9% for HAS-BLED > 3. Significant differences (p = 0.003) occurred for Kaplan-Meier curves for extreme HAS-BLED subgroups. A composite endpoint was most often found in high/very high risk of bleeding patients.

CONCLUSIONS

HAS-BLED, but not CHA2DS2CVASc score, may be a useful tool to predict the prognosis of patients after LAAC. Qualification for LAAC based on the risk of stroke should not differ from qualification for anticoagulation. Despite the worse prognosis of patients with the highest bleeding risk, this group is likely to experience the greatest benefit from reducing the bleeding risk from LAAC.

Clinical Outcomes following Left Atrial Appendage Occlusion: A Single-Center Experience

INTRODUCTION

Percutaneous left atrial appendage closure is an established alternative to anticoagulation therapy for stroke prophylaxis among patients with nonvalvular atrial fibrillation. There are currently no guidelines on the choice of antithrombotic therapy following placement of the Watchman® device, the optimal time to discontinue anticoagulation or the duration of follow-up imaging after device deployment. Our main objective was to evaluate clinical outcomes among these patients.

METHODS

We conducted a retrospective review of patients who received a Watchman® device at Mayo Clinic sites between January 2010 and December 2018. We constructed Cox-proportional hazard models to evaluate the effect of specific variables on clinical outcomes.

RESULTS

231 patients were identified (33% female), median age was 77 years, CHA2DS2-VASc score was 5 and HASBLED score was 4. We found no difference in clinically significant bleeding based on initial antithrombotic choice. However, patients with prior gastrointestinal bleeding were more likely to have a bleeding event in the first 6 weeks following Watchman® implantation (HR 9.40, 95% CI 2.15-41.09). Device sizes of 24-27 mm were significantly associated with a decreased risk of thromboembolic events (HR 0.15, 95% CI 0.04-0.55) compared to 21-mm devices. Peridevice leak (PDL) sizes appeared to either remain the same or increase on follow-up imaging.

DISCUSSION/CONCLUSIONS

This observational study showed no statistically significant difference in bleeding risk related to initial antithrombotic choice. Smaller device sizes were associated with thromboembolic events, and longitudinal PDL assessment using transesophageal echocardiography showed these frequently do not decrease in size. Larger studies are needed.

[Second look: practical diagnostic and therapeutic checks in neurorehabilitation]

Post-acute inpatient neurorehabilitation facilities are increasingly treating patients who are not only severely ill and multimorbid but who are also referred from non-neurological departments. These patients are still often medically unstable so that the previous diagnostics and treatment must be reevaluated and when necessary adapted or supplemented. Certain interdisciplinary diagnostic and therapeutic problems, such as antithrombotic therapy, regularly reoccur. This article presents these problems in a checklist fashion, which should provide indications in individual cases when previously carried out measures need to be questioned and adapted.

Anticoagulation decisions in elderly patients with stroke

Primary and secondary prevention of stroke is often a challenge in elderly patients due to the increase in both thrombotic and hemorrhagic risks with age. In some cases, there is sufficient data in the elderly population to allow recommendations or anticoagulation decisions to be made, such as for the indication of anticoagulation to prevent stroke related to atrial fibrillation (AF) or the choice of oral anticoagulant therapy in this situation. In other situations, the less robust data leave some questions; this is the case for the delay to initiate an oral anticoagulant therapy after an AF-related ischemic stroke, for the management of antithrombotic treatment after a stroke of undetermined cause or after intracranial bleeding or in a high-risk bleeding situation associated with stroke in the elderly subject. These issues will be discussed in this paper.

Impact of Sleep-Disordered Breathing on Functional Outcomes in Ischemic Stroke: A Cardiopulmonary Coupling Analysis

BACKGROUND AND PURPOSE

Cardiopulmonary coupling (CPC) analysis is an easily assessable method to evaluate sleep-disordered breathing (SDB); however, its prognostic impact in patients with acute ischemic stroke needs to be investigated. We performed a CPC analysis using Holter monitoring at the early stage of noncardioembolic ischemic stroke to investigate the prognostic effect of SDB on functional impairment at the 3-month follow-up.

METHODS

A total 615 patients with acute noncardioembolic ischemic stroke who underwent Holter monitoring within 30 days of stroke onset were enrolled from a multicenter, prospective, all-comer cohort. CPC analysis was conducted, and SDB was defined by the presence of narrow-band coupling during sleep time. We investigated the association between SDB and functional impairment at 3 months as measured by the modified Rankin Scale.

RESULT

Narrow-band coupling was present in 191 (31.1%) of 615 patients (mean age 64.5±12.6 years). The narrow-band group showed a significantly higher rate of severe functional impairment (modified Rankin Scale score >2; 45.5% versus 12.9%, P<0.001) and persistent disability (Δmodified Rankin Scale score ≤0; 53.9% versus 39.8%, P<0.001) at the 3-month follow-up. In multivariate analysis, narrow-band coupling was an independent predictor of higher risk of severe and persistent functional impairment at 3 months (odds ratio, 3.98 [95% CI, 2.34-6.78]; P<0.001; and odds ratio, 1.81 [95% CI, 1.23-2.66]; P<0.001, respectively). The results remained consistent after propensity-score matched analysis with 157 patient pairs (C-statistic=0.770).

CONCLUSIONS

SDB assessed by CPC analysis at the early stage of ischemic stroke could predict severe and prolonged functional impairment at 3 months. CPC analysis using Holter monitoring can help predicting functional impairment in acute ischemic stroke.

Resumption of oral anticoagulation after spontaneous intracerebral hemorrhage

Background

Given an ageing population the incidence of both patients suffering from intracerebral hemorrhage (ICH) and those requiring oral anticoagulation will increase. Up to now there are no results from randomized trials available whether or not, and when, ICH survivors should resume OAC. This review summarizes the most important observational studies, and initiated ongoing trials, to help guiding physicians in daily routine decision making.

Findings

Several large observational studies and meta-analyses verified that OAC resumption was associated with a significant reduction of thromboembolic complications and mortality without leading to increased rates of recurrent ICH. OAC resumption seemed further associated with improved functional recovery and favorable long-term outcome. Given the general bleeding risk reduction in patients using Non–vitamin K antagonist oral anticoagulants (NOAC) compared to Vitamin-K-antagonist (VKA), NOAC use should also be preferred after ICH, although specific comparative studies are pending. Patients with lobar ICH need special attention as these patients showed increased ICH recurrence rates, why decision making should include extended diagnostic work-up evaluating cerebral microbleed burden, cortical subarachnoid hemorrhage and superficial siderosis. Further, patients with mechanical heart valves need specific consideration as restarting VKA may be unsafe until two weeks, whereas optimal balancing of hemorrhagic with thromboembolic complications may allow earlier re-initiation one week after ICH. In patients with atrial fibrillation, resumption generally should take place between 4 and 8 weeks after ICH depending on a patient’s individual risk profile. Left atrial appendage occlusion (LAAO) might represent an alternative strategy in high-risk patients. Ongoing clinical trials will clarify whether OAC resumption versus LAAO versus no antithrombotic therapy may represent the best possible secondary stroke prevention in ICH survivors with atrial fibrillation.

Conclusions

According to observational data OAC resumption after ICH seems beneficial and safe. Ongoing clinical trials will create evidence regarding treatment effects of pharmaceutical resumption and interventional alternatives. Yet, individual decision making weighing the patient’s individual thromboembolic versus hemorrhagic risks remains essential.